Dyes of the cyanine series



Patented Jan. 10, 1939 g 1 2,143,383

' UNITED S A S Wi teria DYES, or THE .CYANINE I snares WilhelmSchneider, Dessau, Germany, assignor to Agfa Anscc Corporation,Binghamton, N. Y., a corporation of New York No Drawing. ApplicationJune 24, 1936, Serial No. 87,037. In Germany January 26, 1933 4 Claims.(01. zoo 240) My present invention relates to a new class of by athienyl group may be obtained analogously dyes of the cyanine series andmore particularly to the methods described in the co-pending aptonaphthoxazole trimethinecyanines. It is a plication Ser. No. 661,185filed by Schneider. continuation in part of my application Ser. Not Forsensitizing photographic silver halide 702,260 filed Dec. 13, 1933. iemulsions, the dyes; may be used in a quantity 1 .5

One of its objects is to provide a new class of such as is usual in thecase of the known sensensitizing dyes for'photographi'c emulsions.Ansitizing dyes. This quantity may amount to other object are thenaphthoxazole trimethineabout 10 to 50 milligrams per kilo of emulsioncyanines substituted by alkyl, aryl or aralkyl at ready for being castand containing about 9 per F}; the centralcarbon atom of the trimethenylchain. cent of gelatin, 4.5 per cent of silver halide and l Furtherobjects willbe'seen frorh the detailed the rest water. However, theinvention is not specification'following hereafter. 1 limited to thesequantities and the most suitable According to this invention I' havefound that amount can be found in each case by a w 00 the baseZ-methyI-naphthO-ZCI' :4.5=oxazole corparative experiments.responding'with the following formula form of solutions; suitablesolvents are the alco- 4'} hols, for instance methyl or ethylalcohol-,swhich may be used anhydrous or diluted with water. no Theymaybe incorporated in the emulsion during O i any stage ofitsproduction; preferably, however,

r they are added to the finished emulsion before wQ OHa casting. V

. N Thedyes may also be incorporated in the emul-- or the base2-methyl-naphtho-1'2:4.5oxazole Sign bathing. w m P g h correspondingwith thefollowing formula in a bath in which thedye is dissolved,

Such a treatment may be as follows: The photo- 0 graphic material to besensitized is bathed in a T1 solution containing 1 milligram of the' dyein 1l4 2| about 50 cc. of an aqueous solution of methanol W of 50 percent strength. The material is then m N s i i dried, whereupon it isready for use. L5 l V The following examples serve to illustrate myinvention:

:, yield trimethinecyanines substituted at the cengf fl g iii g gg ftral carbon atom of the trimethenyl chain when r ndin with the formulaconverting according to known methods these anme roml em 18 m g basesinto a quaternary ammonium salt and con.-

The dyes may be added to. the emulsion in the i5;

densing the quaternary ammonium salt with a 4' 2' f? H C2115 H 9"? 2' 4"4o suitably substituted trialkyl-ortho-ester in the l L,

presence of an organic base. Thus, in thecase \T/ 'S g oftriethyl-ortho-propionate the central carbon 5' 6H atom is substitutedby ethyl. In the case r H Br 3 ortho-esters of aromatic carboxylic acidsan aro- 7 \f/ matic radical will be introduced at the central 45 carbonatom of the trimethenyl chain. If the a be Obtained by heating 3 ams off phenyl g is link d t th bon t f [3-f1aphthoxa'zole'dimethylsulfate, 3ccpoi trlethyl the carboxylic group phenyl will be introducedorthoprolfiioinate a Of pyndl e to at the central carbon atom of thetrimethenyl C- fO 1 t0 2 O The y is P chain. If the phenyl group issubstituted by an cipitated from the reaction mixture by means of 50alkyl group, an aralkyl group is introduced at the ether, it is filteredoff, and dissolved in alcohol. central carbon atom. The dyes may also bepro- To the alcoholic solution there is added a solution duced accordingto the co-pending application of potassium bromide, the dye precipitatedby Ser. No. 651,811 filed Jan. 14, 1933, by Koslowsky. means of etherand recrystallized from alcohol,

The dyes substituted at the central carbon atom The alcoholic solutionof the dye has an absorption maximum at a wave length of about 520/LIL.

A silver bromide emulsion containing about 4 to 5 per cent of silveriodide is sensitized for waves from about 500 to 600 with a maximum atabout 565 l by incorporation of the dye.

Example 2.The dye bis-[3-methyl-naphtho- 2.1 24.5-oxazole- (2)l-c-methyl trimethine-cyanine bromide corresponding with the formulaCfia Bl' may be prepared by heating 3 grams of 2-methyl- -naphthoxazoledimethylsulfate, 3 cc. of triethyl orthoacetate and 10 cc. of pyridineto 130 C. for

may be prepared by heating 3 grams of 2-methy1- a-naphthoxazoledimethylsulfate, 3 cc. of triethyl orthopropionate and 10 cc. ofpyridine to 130 C. for about 1 hour. The further working up is asdescribed in Example 1.

The alcoholic solution of the dye has an absorption maximum at a wavelength of about 5181111..

A silver bromide emulsion containing about 4 to 5 per cent of silveriodide is sensitized to waves from 500 to 600 with a maximum at about565 by incorporation of the dye.

Example 4.--The dye bis-[3-methyl-naphtho- 2'.1' :4.5-oxazole- (2)l-;8-thienyl-trimethine-cyanine bromide corresponding with the formulaCH3 Br CH3 may be prepared by heating 3 grams of 2-methyla-naphthoxazoledimethylsulfate, 4 cc. of triethylorthothiophenate and 10 cc. ofpyridine to C. for 1 hour. The further working up is as described inExample 1.

The alcoholic solution of the dye has an absorption maximum at a wavelength of about 5351141..

A silver bromide emulsion containing about 4 to 5 per cent of silveriodide is sensitized to waves from about 515 to 620 with a maximum atabout 590 by incorporation of the dye.

Example 5.The dye bis-[3-methyl-naphtho 1'.2':4.5-oxazole (2) l-p-ethyltrimethine-cyanine bromide corresponding with the formula may beprepared by heating 10 grams of 2- methyl-p-naphthoxazoledimethylsulfate, 7 cc. of ethylisothiopropionic acid anilide and 15 cc.of pyridine in an open vessel to C. for about 1 hour. The dye isprecipitated in form of the bromide and filtered off after cooling.

The alcoholic solution of the dye has an absorption maximum at a wavelength of about 520 A silver bromide emulsion containing about 4 to 5per cent of silver iodide is sensitized to Waves from about 500 toBOO/LIL with a maximum at about 565(L/L by incorporation of the dye.

Example 6.The dye bis-[3-methyl-naphtho- 2".1':4.5-oxazo1 e- (2)l-p-phenyl-trimethine-cyanine bromide corresponding with the formula maybe prepared by heating 3 grams of 2-methyla-naphthoxazoledimethylsulfate, 4 cc. of triethyl orthobenzoate and 10 cc. of pyridineat 135 C. for about 1 hour. The further working up is as described inExample 1.

The alcoholic solution of the dye has an absorption maximum at a wavelength of about 525 A silver bromide emulsion containing about 4 to v 5per cent of silver iodide is sensitized by the dye

